<template>
  <div class="component-upload-image">
    <el-upload
      :action="uploadImgUrl"
      list-type="picture-card"
      :on-success="handleUploadSuccess"
      :before-upload="handleBeforeUpload"
      :limit="limit"
      :on-error="handleUploadError"
      :on-exceed="handleExceed"
      name="file"
      :on-remove="handleRemove"
      :show-file-list="true"
      :headers="headers"
      :file-list="fileList"
      :on-preview="handlePictureCardPreview"
      :class="{ hide: fileList.length >= limit }"
    >
      <el-icon>
        <Plus />
      </el-icon>
    </el-upload>

    <!-- 上传提示 -->
    <div v-if="showTip" class="el-upload__tip">
      请上传
      <template v-if="fileSize"> 大小不超过 <b style="color: #f56c6c">{{ fileSize }}MB</b></template>
      <template v-if="fileType"> 格式为 <b style="color: #f56c6c">{{ fileType.join("/") }}</b></template>
      的文件
    </div>

    <el-dialog
      v-model="dialogVisible"
      title="预览"
      width="800"
      append-to-body
    >
      <img
        :src="dialogImageUrl"
        style="display: block; max-width: 100%; margin: 0 auto"
        alt=""
      >
    </el-dialog>
  </div>
</template>

<script setup>
import { Plus } from '@element-plus/icons-vue'
import modal from "@/plugins/modal.js"

const props = defineProps({
  modelValue: {
    type: [String, Object, Array],
    default: ''
  },
  // 图片数量限制
  limit: {
    type: Number,
    default: 5
  },
  // 大小限制(MB)
  fileSize: {
    type: Number,
    default: 5
  },
  // 文件类型, 例如['png', 'jpg', 'jpeg']
  fileType: {
    type: Array,
    default: () => ['png', 'jpg', 'jpeg']
  },
  // 是否显示提示
  isShowTip: {
    type: Boolean,
    default: true
  }
})

const emit = defineEmits(['update:modelValue'])


const dialogImageUrl = ref('')
const dialogVisible = ref(false)
const baseUrl = import.meta.env.VITE_APP_BASE_API
const uploadImgUrl = import.meta.env.VITE_APP_BASE_API + '/common/Upload'
const fileList = ref([])
const loading = null

const headers = computed(() => {
  const headers = {}
  headers[$store.user.tokenName] = $store.user.getToken()
  return headers
})

const showTip = computed(() => {
  return props.isShowTip && (props.fileType || props.fileSize)
})

// 监听值的变化
watch(
    () => props.modelValue,
    (val) => {
      if (val) {
        // 首先将值转为数组
        const list = Array.isArray(val) ? val : val.split(',')
        // 然后将数组转为对象数组
        fileList.value = list.map(item => {
          if (typeof item === 'string') {
            if (item.indexOf(baseUrl) === -1) {
              item = {name: baseUrl + item, url: baseUrl + item}
            } else {
              item = {name: item, url: item}
            }
          }
          return item
        })
      } else {
        fileList.value = []
      }
    },
    {deep: true, immediate: true}
)

// 删除图片
const handleRemove = (file) => {
  const findex = fileList.value.map(f => f.name).indexOf(file.name)
  if (findex > -1) {
    fileList.value.splice(findex, 1)
    emit('update:modelValue', listToString(fileList.value))
  }
}

// 上传成功回调
const handleUploadSuccess = (res) => {
  fileList.value.push({name: res.fileName, url: res.fileName})
  emit('update:modelValue', listToString(fileList.value))
  loading.close()
}

// 上传前loading加载
const handleBeforeUpload = (file) => {
  let isImg
  if (props.fileType.length) {
    let fileExtension = ''
    if (file.name.lastIndexOf('.') > -1) {
      fileExtension = file.name.slice(file.name.lastIndexOf('.') + 1)
    }
    isImg = props.fileType.some(type => {
      if (file.type.indexOf(type) > -1) return true
      return !!(fileExtension && fileExtension.indexOf(type) > -1)

    })
  } else {
    isImg = file.type.indexOf('image') > -1
  }

  if (!isImg) {
    modal.msgError(`文件格式不正确, 请上传${ props.fileType.join('/') }图片格式文件!`)
    return false
  }
  if (props.fileSize) {
    const isLt = file.size / 1024 / 1024 < props.fileSize
    if (!isLt) {
      modal.msgError(`上传头像图片大小不能超过 ${ props.fileSize } MB!`)
      return false
    }
  }
  modal.openLoading("上传中")
}

// 文件个数超出
const handleExceed = () => {
  modal.msgError(`上传文件数量不能超过 ${ props.limit } 个!`)
}

// 上传失败
const handleUploadError = () => {
  modal.msgError('上传失败')
  modal.closeLoading()
}

// 预览
const handlePictureCardPreview = (file) => {
  dialogImageUrl.value = file.url
  dialogVisible.value = true
}

// 对象转成指定字符串分隔
const listToString = (list, separator = ',') => {
  let strs = ''
  for (const item of list) {
    strs += item.url.replace(baseUrl, '') + separator
  }
  return strs.length > 0 ? strs.slice(0, -separator.length) : ''
}
</script>

<style scoped lang="scss">
// .el-Upload--picture-card 控制加号部分
:deep(.hide .el-upload--picture-card) {
  display: none;
}

// 去掉动画效果
:deep(.el-list-enter-active),
:deep(.el-list-leave-active) {
  transition: all 0s;
}

:deep(.el-list-enter, .el-list-leave-active) {
  opacity: 0;
  transform: translateY(0);
}
</style>

